Iran: US, world powers have delivered a good deal worth supporting

French Foreign Minister Laurent Fabius, second right, German Foreign Minister Frank-Walter Steinmeier, second left, British Foreign Secretary Philip Hammond, left, US Secretary of State John Kerry, center, and Austria's Foreign Minister Sebastian Kurz, right, talk prior to their final plenary meeting at the United Nations building in Vienna, Austria July 14, 2015. After 18 days of intense and often fractious negotiation, diplomats Tuesday declared that world powers and Iran had struck a landmark deal to curb Iran's nuclear program in exchange for billions of dollars in relief from international sanctions, an agreement designed to avert the threat of a nuclear-armed Iran and another U.S. military intervention in the Muslim world. (Joe Klamar/Pool Photo via AP)

The nuclear deal with Iran is one of the most significant nonproliferation agreements in history. It reduces the threat of an Iranian bomb and greatly increases our ability to monitor Tehran’s nuclear program. It deserves the support of members of Congress.

The deal blocks Tehran’s pathways to nuclear weapons capability. Iran’s existing stockpile of enriched uranium will be largely eliminated. Iran will not produce any highly-enriched uranium suitable for weapons development. The number of centrifuges in operation will be reduced greatly. The reactor at Arak will be retooled so that it no longer produces weapons-grade plutonium. The breakout timeline for Iran to develop enough material for a nuclear weapon will be four times longer with a deal than without one.

Iran will be subject to the most intrusive inspections regime ever negotiated. Rigorous and unprecedented inspections will detect any Iranian attempt to renege on the deal. International inspectors will have access to all of Iran’s nuclear sites. The International Atomic Energy Agency will receive assurances that there are no military dimensions of Iran’s nuclear program.

The current regime of nuclear-related sanctions will be suspended only after the International Atomic Energy Agency verifies that Iran has taken necessary steps to curtail its nuclear program. Sanctions on missile development and arms imports will remain in place for several years. Sanctions on Iran will snap back into force if Iran reneges on its commitments. U.S. sanctions on human rights abuse and support for terrorism will remain in place.

Iran will be subject to the most intrusive inspections regime ever negotiated.

The deal isn’t perfect, but it is a very good. It achieves the priority goal of U.S. and international policy of reducing and placing tight controls on Iran’s nuclear capability.

The claim that we can get a ‘better deal later’ is false. The multilateral sanctions regime that brought Iran to the negotiating table is already starting to fray. If the U.S. Congress rejects the deal after the European states, Russia and the United Nations have agreed, international cooperation in sanctioning Iran will disappear.

A rejection of this deal will give Iran a free pass to pursue unrestrained nuclear development. It will mean the loss of the greater verification access Tehran has now accepted. It will damage U.S. relations with our European partners and undermine future efforts at the UN to restrain proliferation.

Without a deal, the U.S. must either accept an Iranian bomb or use military force in an attempt to destroy the country’s nuclear capability. This will require repeated military strikes and would prompt a violent reaction from Iran that could put Israel and other U.S. allies at risk. The result would be more war, terrorism and anti-American sentiment in the Middle East and beyond.

The American people want a deal with Iran. Many polls show that a clear majority of Americans support a negotiated deal with Iran, even with the knowledge that Iran will receive sanctions relief and retain a civilian nuclear program. A majority of Americans oppose military action against Iran, and have done so consistently for many years.

The choice is clear. Support the current nuclear deal or face a future of more proliferation and war.

Nuclear policy and sanctions expert David Cortright is director of policy studies at the University of Notre Dame’s Kroc Institute for International Peace Studies.